Machine Tool, in Particular Hand-Held Machine Tool, Comprising a Releasable Dust Collection Receptacle

ABSTRACT

A machine tool comprises a dust collection receptacle that is releasably connected to the machine tool. A blow-off neck is arranged on a housing part, and a receptacle neck is arranged on the dust collection receptacle. The two necks can be axially plugged into each other. In the plugged state, supporting surfaces on the dust collection receptacle and on the housing part rest against each other in a planar manner, said supporting surfaces extending at an angle from the longitudinal axis of the plugged necks. The face of one neck forms a first supporting surface.

The invention relates to a machine tool, in particular a hand-held machine tool such as a random orbital sander or an orbital sander, according to the preamble of claim 1.

PRIOR ART

A hand-held machine tool designed as a grinding machine with an electric drive motor for driving a tool is described in DE 10 2006 061 635 A1. To collect the grinding dust that accumulates as a workpiece is worked, the housing of the hand-held machine tool is connected to a dust collection receptacle, which has a receptacle connector, which can be plugged onto a blow-out connector on the housing. The housing sides facing one another on the dust collection receptacle and on the housing are convexly shaped and bear against one another in a planar manner when the dust collection receptacle is assembled. If the dust collection receptacle is rotated about the longitudinal axis of the receptacle connector, the dust collection receptacle is slid axially away from the housing due to the three-dimensional formation of the supporting surfaces bearing against one another, whereby the release of the dust collection receptacle from the housing is simplified.

DISCLOSURE OF THE INVENTION

The object of the invention is to develop a machine tool using simple constructional measures alongside a compact embodiment such that controlled release of a dust collection receptacle from the machine tool is possible.

This object is achieved in accordance with the invention by the features in claim 1. The dependent claims specify expedient developments.

The machine tool according to the invention is provided with a dust collection receptacle, which can be fastened to the housing and is used to collect grinding dust or chips that accumulate as a workpiece is worked. The machine tool is a grinding or shaving machine, which drives a tool via a drive device, in particular an electric drive motor, said tool being used to work a workpiece. In accordance with a preferred embodiment the machine tool is a hand-held machine tool, in particular a grinding machine such as an orbital rotary sander or a rotary sander. The machine tool is provided with a dust extraction device for extracting and conveying the grinding dust into the dust collection receptacle.

The dust collection receptacle is releasably connected to a housing part of the machine tool. The connection is made by plugging a receptacle connector, which is formed on the dust collection receptacle, into a blow-out connector, which is formed on a housing part. The two connectors can be plugged axially into one another to produce the connection. In the connected state, the connectors have a common longitudinal axis and can be rotated relative to one another about said longitudinal axis. The blow-out connector is part of the housing of the machine tool or is a constituent of a component connected to the housing, for example an extraction hood, which is arranged directly adjacent to the tool of the machine tool and via which abraded particles produced as a workpiece is worked are extracted. The component having the blow-out connector has various functions in principle, for example forms a housing for a bearing, etc. Air-guiding functions can be integrated into the component, for example a fan outlet spiral or feed lines to the blow-out connector.

Supporting surfaces are provided both on the dust collection receptacle and on the housing part and bear against one another in a planar manner when the dust collection receptacle is assembled. The supporting surfaces are arranged at an angle to the longitudinal axis of the plugged connectors, said angle lying in an angular range greater than 0° and less than 90°. Due to the angular orientation of the supporting surfaces, an axial displacement of the dust collection receptacle relative to the housing part is achieved simultaneously as the dust collection receptacle is rotated about the connector longitudinal axis, whereby the release of the dust collection receptacle from the housing of the machine tool is considerably facilitated. In accordance with a further expedient embodiment the supporting surfaces are arranged at an angle of 45° at most to the plane running orthogonally to the longitudinal axis of the connector.

With the embodiment according to the invention the end face of one of the connectors forms a first supporting surface. In contrast to the embodiments known from the prior art, it is thus possible to dispense with a large-area embodiment of the supporting surface. In addition to a stop function, the end face of one connector thus also undertakes the task of being able to easily release the dust collection receptacle from the housing. A large-area design of the supporting surface, as is provided in the prior art, is not necessary with the embodiment according to the invention. A compact design on the whole is achieved with the invention.

In accordance with an advantageous embodiment the receptacle connector has a larger diameter than the blow-out connector and can be slid onto the blow-out connector. In this variant it is expedient for the end-face, first supporting surface to be located on the receptacle connector and to be supported in the plugged state against a second supporting surface, which is formed on the housing part receiving the blow-out connector. The second supporting surface is formed in a manner complementary to the first supporting surface on the end face of one connector and adopts an annular form. The second supporting surface thus surrounds the connector of smaller diameter annularly.

In principle, embodiments in which the first, end-face supporting surface is arranged on the blow-out connector and the correspondingly formed second supporting surface is arranged on the dust collection receptacle or the receptacle connector are also possible, however. Furthermore, embodiments in which the first, end-face supporting surface is located on the connector of smaller diameter are also possible, wherein, in this case, the second supporting surface is arranged within the connector of larger diameter, for example in the form of a recumbent, peripheral annular shoulder. The connector of smaller diameter carrying the end-face supporting surface may be both the receptacle connector and the blow-out connector.

In accordance with a further advantageous embodiment the end-face, first supporting surface has a plurality of successively adjoining portions of alternating inclination as viewed in the peripheral direction. Each portion is thus arranged at an angle between 0° and 90° to a plane orthogonal to the longitudinal axis of the connector, wherein directly adjacent portions have different angles. It may be expedient to provide a total of just two angle categories for the alternating portions.

The end-face supporting surface expediently consists exclusively of straight or planar portions. In a further, advantageous embodiment, at least some of the portions are curved, wherein the tangent at the curved portions encloses an angle between 0° and 90° to the longitudinal axis of the connector.

It is also expedient for the portions to extend with a different inclination over the entire periphery at the end face of the connector. In accordance with an alternative embodiment the portions extend only over an angular range less than 360° in the peripheral direction at the end face of the connector.

It is also expedient for the connector of larger diameter to have a latching element on the inner wall, said latching element being latched to an associated, further latching element on the lateral surface of the second connector of smaller diameter in the plugged state. In the assembled state, blow-out connectors and receptacle connectors are held securely against one another via the latched connection. To release the latched connection the connectors merely have to be rotated relative to one another about the connector longitudinal axis, whereupon the connectors are axially displaced in the release direction due to the angular orientation of the supporting surfaces and the latched connection is thus released.

In accordance with a further, expedient embodiment the latching element on the inner wall of the connector is formed as a peripheral latching curvature, which is associated with a latching groove in the lateral surface of the second connector, wherein, in the latched position, the latching curvature lies in the latching groove. In this case it may be expedient to provide in the lateral surface of the connector of smaller diameter a multiplicity of latching grooves arranged parallel to one another, whereby the security against accidental release of the dust collection receptacle from the housing of the machine tool is increased. The connectors are slid axially over one another during the assembly process until the supporting surfaces bear against one another as far as their limit.

In accordance with a further advantageous embodiment the latching element, which is arranged on the inner side of the connector of larger diameter, is located axially on the side of the connector facing away from the end face. This embodiment has the advantage that, for example in the design as a latching curvature and with a multiplicity of latching grooves over the lateral surface of the smaller connector, merely a low resistance has to be overcome until the latched position is reached. With regard to increased security against accidental release, it is expedient, by contrast, to arrange the latching curvature adjacent to the end face with the supporting surface, wherein, in this case, a plurality of latching grooves has to be overcome before the final latching position is reached.

Further advantages and expedient embodiments are to be inferred from the further claims, the description of the figures, and the drawings, in which:

FIG. 1 shows a perspective view of an extraction hood for a machine tool with blow-out connectors arranged thereon and a dust collection receptacle with a receptacle connector,

FIG. 2 shows the extraction hood and the dust collection receptacle in the connected state,

FIG. 3 shows an enlarged illustration from the connection region between the extraction hood and the dust collection receptacle,

FIG. 4 shows a perspective individual illustration of the extraction hood with the blow-out connector,

FIG. 5 shows an individual illustration of the receptacle connector of the dust collection receptacle,

FIG. 6 shows a longitudinal section through the receptacle connector,

FIG. 7 shows a section through the blow-out connector and the receptacle connector in the partially plugged state, and

FIG. 8 shows a section through the blow-out connector and the receptacle connector in the assembled state.

Like components are provided with like reference signs in the figures.

FIG. 1 shows an extraction hood 1 and a dust collection receptacle 2, which is to be releasably connected to the extraction hood 1, as part of a hand-held machine tool, in particular a grinding machine, for example an orbital rotary sander or rotary sander. The extraction hood 1 covers the tool of the hand-held machine tool and is used to extract abraded particles or grinding dust accumulating as a workpiece is worked. Air-guiding functions can be integrated into the extraction hood 1 so as to improve the removal of the grinding dust.

A blow-out connector 3, onto which a receptacle connector 4 formed in one piece with the dust collection receptacle 2 can be plugged, is formed in one piece with the extraction hood 1. The extraction hood 1 in the form of a housing component is normally fabricated from plastics material, as is the dust collection receptacle 2, wherein embodiments made of metal may also be considered. The blow-out connector 3 is provided with a plurality of latching grooves 5 over its outer lateral surface. The outer diameter of the blow-out connector 3 including the latching grooves 5 is dimensioned with respect to the inner diameter of the larger receptacle connector 4 such that the receptacle connector 4 can be slid axially onto the blow-out connector 3. In the slid-on, connected state, the dust collection receptacle 2 is connected in a flow-tight manner to the extraction hood 1 so that the extracted grinding dust is conducted inside the dust collection receptacle 2 via the blow-out connector 3 and the receptacle connector 4 without false airflows. In the connected state, which is illustrated in FIGS. 2 and 3, the blow-out connector 3 and the receptacle connector 4 have a common longitudinal axis 6. The longitudinal axis 6 is simultaneously the longitudinal axis of the dust collection receptacle 2 formed as an elongate body. The longitudinal axis 6 extends at least approximately radially relative to the axis of a central recess in the extraction hood 1, which is used to pass through a drive shaft.

In the assembled state, which is illustrated in FIGS. 2 and 3, the end face 7 of the receptacle connector 4 bears against the extraction hood 1 and contacts a supporting surface 8. The end face 7 of the receptacle connector 4 forms a first supporting surface, whilst the contact surface 8 at the extraction hood 1 forms a second supporting surface, wherein the first and second supporting surface 7, 8 are formed in a manner complementary to one another so that there is planar contact between the supporting surfaces in the connected state according to FIGS. 2 and 3.

As can be inferred from FIGS. 3 and 5, the first supporting surface 7 at the end face of the receptacle connector 4 is formed of a series of portions 9, which are each formed in a planar manner but are arranged at an angle to a plane 10 (FIG. 3) running orthogonally to the longitudinal axis 6, said angle being greater than 0°, but less than 90° and preferably being 45° at most. Portions 9 at the end face 7 of the receptacle connector 4 directly adjacent in the peripheral direction are in each case arranged at a different angle to the longitudinal axis 6 or the plane 10. Due to the angular orientation of the portions 9 at the end face 7, a rotation of the dust collection receptacle 2 including the receptacle connector 4 about the longitudinal axis 6 causes the receptacle connector 4 and the dust collection receptacle 2 to be distanced axially from the blow-out connector 3 and the extraction hood 1. The connection between the blow-out connector and the receptacle connector can thus be released.

The second supporting surface 8 at the extraction hood 1 surrounds the blow-out connector 3 annularly, as can be inferred from FIG. 4 for example. The second supporting surface 8 has the same angularly oriented portions as the first supporting surface 7 at the end face of the receptacle connector 4.

In the plugged state the blow-out connector 3 and the receptacle connector 4 are interconnected via a latched connection. The latched connection is achieved by means of latching elements, wherein a latching curvature 11 is arranged as a latching element on the inner wall of the receptacle connector 4 having a larger diameter compared to the blow-out connector 3 and protrudes annularly against the inner wall of the receptacle connector 4 of reduced inner diameter. The latching curvature 11 cooperates with the latching grooves 5 in the outer lateral surface of the blow-out connector 3, which likewise form latching elements. The latching curvature 11 is located at an axial distance from the free end face 7 of the receptacle connector 4.

As can be inferred from FIGS. 7 and 8, the latching curvature 11 reaches a latched position with the latching grooves 5 in the outer lateral surface of the blow-out connector 3 when the receptacle connector 4 is slid onto the blow-out connector 3. So as to assume the latched position according to FIG. 8, the receptacle connector 4 has to be slid on axially until the supporting surfaces 7 and 8 are in contact. In this case, the latching curvature 11 reaches into a latching groove 5, whereby a latched closure between the blow-out connector 3 and the receptacle connector 4 is produced in the axial direction.

To release the latched connection, merely a relative rotation between the blow-out connector and the receptacle connector 4 has to be generated, whereupon the receptacle connector 4 is displaced axially away from the extraction hood 1 due to the angular orientation of the supporting surfaces with respect to the plane orthogonal to the longitudinal axis. In this case, the latched curvature 11 disengages from the associated latching groove 5 so that the latched connection is cancelled and the receptacle connector 4 can be removed axially without resistance. 

1. A machine tool, comprising: a dust collection receptacle configured to be releasably connected to the machine tool; a blow-out connector located on a housing part; and a receptacle connector located on the dust collection receptacle, wherein the blow-out connector and the receptacle connector are configured to be axially plugged into one another in a plugged state, wherein, in the plugged state, supporting surfaces on the dust collection receptacle and the housing part bear against one another in a planar manner, wherein the supporting surfaces are oriented at an angle relative to a longitudinal axis of the connectors in the plugged state, and wherein an end face of one connector of the blow-out connector and the receptacle connector defines a first supporting surface of the supporting surfaces.
 2. The machine tool as claimed in claim 1, wherein: the receptacle connector is configured to be slid onto the blow-out connector, and an end-face of the receptacle connector defines the first supporting surface.
 3. The machine tool as claimed in claim 1, wherein the end-face defining the first supporting surface includes a plurality of successive portions of alternating inclination in a peripheral direction.
 4. The machine tool as claimed in claim 1, wherein the end-face defining the first supporting surface is curved, at least over portions, and a tangent at the curved portions defines an angle relative to the longitudinal axis of the connectors.
 5. The machine tool as claimed in claim 1, wherein: a first connector of the receptacle connector and the blow-out connector has a larger diameter than a second connector of the receptacle connector and the blow out connector, and the first connector includes a latching element on an inner wall, said latching element being latched to an associated latching element on a lateral surface of the second connector in the plugged state.
 6. The machine tool as claimed in claim 5, wherein the latching element on the inner wall of the first connector includes a peripheral latching curvature configured to engage a peripheral latching groove in the lateral surface of the second connector.
 7. The machine tool as claimed in claim 6, wherein the lateral surface of the second connector includes a plurality of latching grooves located parallel to one another.
 8. The machine tool as claimed in claim 5, wherein the latching element on the inner wall of the first connector is located axially on a side of the first connector facing away from an end face of the first connector.
 9. The machine tool as claimed in claim 1, wherein a second supporting surface of the supporting surfaces annularly surrounds a connector of the receptacle connector and the blow-out connector having a smaller diameter.
 10. The machine tool as claimed in claim 1, wherein: the housing part includes an extraction hood, and the blow-out connector is located on the extraction hood.
 11. The machine tool as claimed in claim 1, wherein the supporting surfaces are arranged at an angle of at most 45° relative to a plane defined orthogonally to the longitudinal axis of the connectors. 